Apparatus for pipe-bending, both in new plant or to repair serviceable plants wherein pipes are used for fluid flow--for example for hot and/or cold water for sanitary and/or heating fittings--call usually for requirements regarding the practical use of same, particularly when the bending operation is to be carried out at the site of the plant and when pipes having a wide range of diameters and small thickness (less than 1 mm) are to be bent by means of a single bending apparatus.
Attempts have been made to produce portable pipe bending apparatus to be used on site, the features of which considerably reduce the overall dimensions and make easier the bending operation. In spite of these attempts, the bending apparatus of the prior art is not fully satisfactory in its constructive and operative purposes, also because the pipe bending operation being carried out by same does not avoid any undesirable uneven stretching of the pipe which might even be evidenced at a subsequent time. Failures and/or wrinkle lines may be formed on the pipe during a bending operation when the material is sensitive to stretching stresses and a flattening may also be remarked on the bent pipe. These undesirable uneven stretching effects are, for example, much more probable when pipes of hard copper are to be bent and the portable pipe bending apparatus requires the best attention of the operator during the bending operation, which in any case cannot be carried out rapidly by means of bending apparatus of the prior art which is usually controlled manually.
On the other hand, the increasing installation of systems for heating and sanitation, particularly for cold and hot water flow, as well as the increasing use of pipes formed of materials sensitive to stretching stresses, increases the importance not only of a speedy and actually satisfactory bending operation and an easy installation, but also of an economical pipe-bending construction and production and the pipe installation costs.
By using the pipe bending apparatus in accordance with the present invention, the bending operation is in any case speedy and some embodiment of the same are possible in order to be suitable to the features of the pipe to be bent.